1. Field of the Invention
The present invention relates to a recording/reproducing system and a recording/reproducing process for adding additional information to information signals, such as image signals, and recording the resultant signals on a recording medium, and for, in reproduction, picking up the additional information added to the information signals and then performing control for reproduction; and a recording device and a reproducing device for use in the aforementioned system and process.
2. Description of Related Art
Recently, there have been provided many reproducing devices such as a digital VTR and a reproducing device for a DVD (Digital Video Disc), and softwares which can be reproduced by use of these devices. Digitized image signals and sound signals have been easily reproduced at home so that images with good image quality can be watched and sounds with good sound quality can be listened to.
Furthermore, there have been also provided abundant image signals and sound signals, or programs through Internet and recording media such as a CD-ROM (Compact Disc ROM), and the digitized softwares provided through Internet and the recording media such as a CD-ROM have been widely used in a personal computer or the like.
However, it is feared that the softwares such as digital image signals provided abundantly in such a manner as above are copied without any restriction. Hitherto, therefore, various copy preventing methods have been adopted to prevent illegal copying of information signals such as image signals and sound signals.
As one of the copy preventing methods, there is known a copy limiting system over plural generations called CGMS (copy generation management system) In this system, 3-stage classified copy control information, i. e., information that copying is free, that copying is allowable for the first generation, or that any copying is prohibited is embedded on an information signal. For example, in the case wherein copying is free, wherein copying is allowable for the first generation, or wherein any copying is prohibited, 2-bit copy control information of xe2x80x9c00xe2x80x9d. xe2x80x9c10xe2x80x9d or xe2x80x9c11xe2x80x9d is embedded in the information signal, respectively. However, in the case wherein any copying is prohibited, the copy control information is not embedded in the information signal.
When the information signal is copied on a recording medium, the copy control information embedded in the information signal according to the CDMS is detected, and then the copy control is performed in accordance with the detected copy control information. In this case, if any copy controlling signal is not detected, the information signal cannot be copied. This is because in the case wherein any copying is prohibited, any copy control information is not embedded.
As described above, control can be performed not only for copying-prohibition or copying-allowance, but also for copying-allowance only for the first generation. Thus, flexible copy preventing control has been able to be performed.
In the case wherein copy preventing control is performed according to the CGMS, however, suppliers of information signals have a desire that copying of the information signals is limited to copying by an individual, for example, at home, i.e., copying for private use even if the copy controlling information that copying is free or that copying is allowable for the first generation is added to the information signal.
In other words, there are no problems in the case wherein an individual copies the information signal on a recording medium at home and then the individual uses the copied information signal; however, it is not preferred for the suppliers of information signals that even information signals the copying of which is allowable are copied many times so that the copied information signals will spread widely to the public.
In order to prevent such spread of copied information signals, it is considered that the suppliers of information signals, in supplying the signals, more frequently add the copy control information that any copying is prohibited to the information signals for supply, or that the cost for supplying information signals becomes expensive. This case is not preferable since copying for private use is also limited.
In the light of the above, an object of the present invention is to provide an information signal recording/reproducing system and an information signal recording/reproducing process for making it possible to limit even the information signal the copying of which is allowable to be copied for private use; and recording and reproducing devices for use in this system and this method.
The present invention is an information signal recording/reproducing system, using a recording medium having thereon an area which is different from an area for recording information signals and which medium-related information, which is information on the recording medium, is beforehand recorded in, or having a section accompanying the recording medium in which the medium-related information is beforehand recorded; and comprising a recording device section for recording the information signals on the recording medium and a reproducing device section for reproducing the information signals recorded on the recording medium;
the recording device section comprising:
recording-side medium-related information reading means for reading the medium-related information from the recording medium, or from the section accompanying the recording medium;
information adding means for adding the medium-related information read by means of the recording-side medium-related information reading means to the information signals; and
recording means for recording the information signals to which the medium-related information is added by means of the information adding means on the recording medium;
the reproducing device section comprising:
reproducing-side medium-related information reading means for reading the recording medium, or from the section accompanying the recording medium;
information signal reading means for reading the information signals from the recording medium;
detecting means for detecting the medium-related information added to the information signals from the information signal reading means;
determining means for determining whether or not the medium-related information from the reproducing-side medium-related information reading means is consistent with the medium-related information from the detecting means; and
reproduction controlling means for carrying out control for reproducing the information signals only when the medium-related information from the reproducing-side medium-related information reading means is consistent with the medium-related information from the detecting means.
According to the information signal recording/reproducing system of the present invention, when information signals attempt to be recorded, the medium-related information is read from the recording medium on which the information signals are recorded or from the section accompanying the recording medium by means of the recording-side medium-related information reading means. The read medium-related information is added to the information signals by means of the information adding means, and then the information signals to which the medium-related information is added are recorded on the recording medium. The medium-related information is, for example, information intrinsic to every recording medium, and is, in the case of the recording medium is a disc, a serial number recorded in a TOC (Table Of Content) of the disc.
When the information signals recorded on the recording medium are reproduced, the medium-related information of the recording medium is read from the recording medium to be reproduced or the section accompanying the recording medium by means of the reproducing-side medium-related information reading means. The medium-related information added to the information signals to be reproduced is detected by means of the detecting means.
The information signals are reproduced when the medium-related information read by means of the reproducing-side medium-related information reading means is consistent with the medium-related information detected from the information signals by means of the detecting means.
In short, when recording process is performed in an ordinary manner, the medium-related information added to the information signals is consistent with the medium-related information of the recording medium on which the information signals are recorded. However, when copying is carried out in other manner, for example, when the whole of the information recorded on the recording medium, as it is, is copied on another recording medium, the medium-related information of the recording medium is not consistent with the medium-related information of the information signals recorded on this.
Therefore, when the medium-related information added to the information signals is consistent with the medium-related information of the recording medium on which the information signals are recorded as described above, the information signals are decided to be information signals copied for private use in an ordinary manner and then are reproduced. On the contrary, when the medium-related information added to the information signals is not consistent with the medium-related information of the recording medium on which the information signals are recorded, the information signals are decided to be information signals copied in other manner than the ordinary manner and then are not reproduced.
Thus, the information signals copied in the ordinary manner by means of the recording device section can be reproduced without any problem. However, the information signals copied in other manner than the ordinary manner cannot be reproduced. Accordingly, it is possible to prevent copying of the information signals for other purposes than private use.